You are here

The Goldenasters

Goldenasters (and camphor weeds) in the usual sense are common wildflowers and weeds of the summer and fall floras of most of the mid and subtropical latitudes of North America. Based on cladistic/ phylogenetic analyses of chloroplast DNA data (Suh and Simpson 1990; Morgan and Simpson 1992; Lane et al. 1996) and morphological and anatomical data (Nesom 1991d; Semple 1996), there are seven genera (or possible genera) in the "goldenaster group":Bradburia Torr. & Gray, CroptilonRaf.,Chrysopsis (Nutt.) Ell. nom. cons.,Heterotheca Cass., Noticastrum DC.,Pityopsis Nutt., Osbertia Greene, and Tomentaurum Nesom. These mostly herbaceous perennials are aster-like members of the Fam. Compositae: Tribe Astereae that have yellow rays (or sometimes purplish in Noticastrum or tinted reddish abaxially in Osbertia), yellow disc florets and fruits usually with a double pappus consisting of a short outer whorl of generally linear scales a millimeter or less in length and an inner whorl of long barbellate bristles about the length of the corolla tube. Nesom (1994a) proposed treating these genera as the subtribe Chrysopsidineae Nesom. Osbertia E.L. Greene was included in the subtribe by Nesom, although it has a single pappus whorl. Using chloroplast DNA data, Lane et al. (1996) did not find that it grouped with the other genera of the Chrysopsidineae included in their study. Thus, there is supporting evidence for the "goldenaster group" being treated as a subtribe with some questions about its membership.

Semple (1977) and Semple et al. (1980) provided the framework on which rests recognition of the three genera historically thought of as the goldenasters:Chrysopsis, Heterotheca, and Pityopsis. Contrasting revisions of the camphor weeds (H. sect. Heterotheca) were published by Wagenkneckt (1960) and Nesom (1990). Semple (1981) revised the eastern goldenasters (Chrysopsis sensu Semple 1977). The grass-leaved goldenasters Pityopsis were revised by Semple and Bowers (1985). The monospecific H. sect. Ammodia (Nutt.) was revised by Semple et al. (1988). The at-the-time monotypicBradburia was studied by Semple and Chinnappa (1984). Zardini (1985) monographed Noticastrum in South America. Osbertia was reviewed by Turner and Sundberg (1986) supplemented with studies by Nesom (1991c) and García Arévalo (1991). The monotypic Tomentaurum was described by Nesom (1991b, 1991e). Semple (1996) presented an overview of all genera in the "goldenaster group" in a revision of Heterotheca sect. Phyllotheca, which includes the H. villosa complex.